Side Port Catheter Device With Imaging System and Method For Accessing Side Branch Occlusions

ABSTRACT

A medical device and method are provided for accessing a side branch in an artery utilizing an on-board imaging device. The device includes a catheter having a sidewall, an internal lumen, and a side port formed through the sidewall. A perforating guide wire has a proximal portion within the internal lumen and a distal portion arranged to be movable out of the side port. The guide wire can be delivered through the side port to a side branch artery when the catheter is deployed to a location with the side port aligned with the side branch artery. In one embodiment, the catheter includes an on-board imaging system disposed adjacent the side opening. The imaging system images tissue adjacent the side opening to assist with alignment of the guide wire to enter a side branch and/or cross an occlusion within the side branch.

RELATED APPLICATIONS

This application is a continuation-in-part of U.S. patent applicationSer. No. 11/838,297 filed on Aug. 14, 2007, and claims priority of U.S.Provisional Application No. 60/837,900 filed on Aug. 14, 2006. Thecontent of these prior applications are incorporated herein byreference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to catheters and methods oftreating a stenosis of an artery. In particular, the present inventionrelates to catheters and methods for accessing chronic total occlusions(CTOs) in arteries caused by the buildup of arterial plaque tissue.

2. Description of the Related Art

Chronic total occlusion (CTO) is a condition where arterial plaquetissue grows to complete stenosis of an artery and prohibits blood flow.A CTO is formed by the agglomeration of three separate physiologicalmaterials: (i) cholesterol or fat, (ii) collagen or fibrous matter, and(iii) calcium-based deposits. A CTO is also often referred to as afunctional occlusion.

There are two causal pathogenic phenomena often associated with theformation of a CTO. The first is the late development of an acuteocclusion. The second is the progressive occlusion of a long-term highdegree stenosis. Both involve a pre-existing plaque or thrombus to whichthe fat and fibrous material adhere, building up until a blockage of theblood vessel occurs. A CTO 10 will sometimes form in a side branch 11 ofan artery 12 as shown in FIG. 1, which is difficult to access usingconventional catheters and surgical techniques.

Physicians currently attempt to perforate CTOs 10 in side branches 11using a stiff guide wire 13 as shown in FIG. 2. A small catheter 14 isused to position the guide wire 13 at the occlusion 10.

Another conventional technique involves the use of a curved catheter 15to align a perforating guide wire 16 with the angle of the side branch11, as shown in FIG. 3. One of the primary problems with this approachoccurs when a compressive force is applied to the guide wire 16. Theguide wire 16 must be pushed to perforate the occlusion 10 and as it ispushed, the catheter 15 in which the guide wire 16 is contained reactsin a negative manner, as shown in FIG. 4. As can be seen, the catheter15 will be pushed and/or rotated away from the side branch 11, ormisaligned with the side branch 11, as compressive force is exerted onthe guide wire 16. The restraint offered by the catheter 15 is limitedbecause it must be made of a material that is soft enough not to injurethe arteries as it is advanced into the vascular system. Catheters arelimited as to the amount of stiffness the catheter can contain before itwill injure the artery as it is aligned with the side branch. Inaddition, the curvature of the catheter can cause substantial “whip” asa physician torques the catheter to align it with the side branch.

A compliant balloon 17 can be attached to the catheter 18 to help limitthe reaction forces on the catheter 18, as shown in FIG. 5. The balloon17 is inflated through a separate lumen in the catheter 18. The balloon17 allows for more stability in the catheter 18 as it is used. However,it still suffers from the cantilever type positioning exhibited in FIG.4. In addition, it is still subject to whip caused by the curvature ofthe catheter as torque is applied to position the catheter.

There is a need in the industry for improved devices and methods toassist surgeons in accessing CTOs in side branches of arteries.

SUMMARY

The present disclosure provides an occlusion crossing system utilizingan imaging system carried by the catheter to assist in guiding theadvancement of the occlusion penetrating device.

In one aspect, the present disclosure provides a method of crossing anocclusion within a vessel. The method comprises positioning a catheterwithin a vessel of a patient, the catheter including an imaging element,a steering assembly and an occlusion crossing wire extendible through anexit opening in the catheter. The method includes advancing the imagingelement through a main vessel to a position adjacent an occlusion of aside vessel and imaging the occlusion along with a portion of the sidevessel. Once the vessel has been imaged, the catheter can be rotated toalign the exit opening with the occlusion and the crossing wire can beadvanced through the exit opening and into the occlusion. The steeringassembly is operable to change the trajectory of the crossing wire.

In still a further form, the present disclosure provides a method oftreating an internal structure within a patient. The method includespositioning a catheter adjacent a structure to be treated, the catheterincluding an imaging element, a steering assembly and a therapy deliverydevice extendible through an exit opening in the catheter, the steeringassembly operable to adjust the trajectory of the therapy deliverydevice as it extends through the exit opening. The method includesadvancing the imaging element to a position adjacent the structure to betreated, imaging the structure to be treated with the imaging elementand aligning the exit opening with the structure to be treated. Once theexit opening is properly aligned, the therapy delivery device can beadvanced through the exit opening and toward the structure to betreated. In one aspect, the trajectory of the therapy device can becontrolled by the steering assembly while advancing the therapy deliverydevice.

In yet a further feature, the present disclosure provides a vesselocclusion crossing system. The system includes a catheter body having alumen, an imaging element disposed on a distal portion of the catheter,a crossing wire slidably disposed within at least a portion of thecatheter, and a steering assembly for changing the direction of thecrossing wire after exit from the catheter body.

These and other aspects of the present disclosure will become apparentfrom the following detailed description and associated drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more clearly appreciated as thedisclosure of the present invention is made with reference to theaccompanying drawings. In the drawings:

FIG. 1 shows a vessel in a coronary vascular system with a side branchthat is totally occluded.

FIG. 2 shows a conventional technique used to perforate an occlusionwith a stiff guide wire and a small catheter to position the guide wireat the occlusion.

FIG. 3 shows a conventional technique that uses a curved catheter and/orcurved catheter/guide wire combination to align the perforating guidewire with the angle of the side branch.

FIG. 4 illustrates the reactive forces on the catheter when the guidewire is pushed to perforate the occlusion using the conventionaltechnique.

FIG. 5 shows a catheter with a balloon attached to help limit thereaction of the catheter as the guide wire is pushed into the occlusion.

FIG. 6 shows a catheter according to an embodiment of the presentinvention having a side port through a sidewall for delivering a guidewire to a side branch occlusion in an artery.

FIG. 7 shows another embodiment of the present invention in which thecatheter contains a single lumen and side port through which the guidewire is passed.

FIG. 8 shows another embodiment of the present invention in whichsupport balloons are used to stabilize the catheter during usage.

FIGS. 9 and 10 show another embodiment of the present invention in whicha single support balloon is centered over the side port and attached tothe catheter shaft at the proximal and distal ends of the balloon andaround the side port.

FIG. 11 shows another embodiment of the present invention in which a“hot dog bun”-shaped balloon is centered about the side port andattached to the catheter shaft.

FIG. 12 shows another embodiment of the present invention in which twolumens are provided in the catheter; one lumen leading to the side portand the other lumen providing a passage for inflating support balloonsattached to the catheter.

FIGS. 13 and 14 are side and end views of another embodiment of thepresent invention in which a channel is provided for inserting thecatheter over a guide wire previously placed in the non-occluded artery.

FIGS. 15 and 16 are side and end views of another embodiment of thepresent invention in which a guide wire lumen is provided on theexterior of the primary catheter with a support balloon.

FIG. 17 shows another embodiment of the present invention in which aguide wire lumen is provided on the exterior of the primary catheterwithout a support balloon.

FIG. 18 shows another embodiment of the present invention in which noextension of the catheter extends past the side port, and a molded tipis provided to facilitate movement of the exiting guide wire.

FIGS. 19 to 21 show another embodiment of the present invention in whichthe side port is movable relative to the base catheter to change theangle at which the guide wire exits the catheter.

FIG. 22 shows another embodiment of the present invention in whichtelescoping sleeves are used to change the angle at which the guide wireexits the catheter.

FIG. 23 shows another embodiment of the present invention in whichtelescoping inner and outer tubes having offset ports at their distalends are used to change the angle at which the guide wire exits thecatheter.

FIGS. 24 and 25 show the catheter of FIG. 23 with the inner tube atdifferent positions relative to the outer tube to cause the guide wireto exit the catheter at different angles.

FIGS. 26 and 27 show another variation of the catheter of FIG. 23 inwhich the exit port of the outer telescoping tube is offset from thelongitudinal axis of the catheter.

FIG. 28 illustrates a first embodiment of an occlusion crossing systemincorporating an imaging system.

FIGS. 29 and 30 illustrate a further embodiment of an occlusion crossingsystem incorporating an imaging system.

FIGS. 31-33 illustrate still a further embodiment an occlusion crossingsystem incorporating an imaging system.

FIG. 34 illustrates a display device displaying an image associated withthe imaging system.

DETAILED DESCRIPTION OF THE INVENTION

Side port catheters and methods for accessing side branch occlusions inarteries according to the present invention will now be explained indetail with reference to the accompanying drawings.

FIG. 6 shows a catheter 20 having a sidewall 21 and an internal lumen22. A side port 23 is formed through the sidewall 21 of the catheter 20.A perforating guide wire 24 is provided in the catheter 20 for accessingand treating a side branch occlusion 10 in an artery 12. The guide wire24 has a proximal portion 25 within the internal lumen 22 of thecatheter 20 and a distal portion 26 arranged to be movable out of theside port 23. The side port 23 is arranged to bend the guide wire 24away from a longitudinal axis of the catheter 20 as the guide wire 24passes through the side port 23. The guide wire 24 can thus be deliveredthrough the side port 23 to the occlusion 10 in the side branch 11 ofthe artery 12.

In FIG. 6, a distal portion 27 of the catheter 20 extends for somedistance past the side port 23 to add stability to the catheter 20 whilethe guide wire 24 is being delivered through the side port 23. Theperforating guide wire 24 may be either straight or formed with apre-curved tip at its distal portion 26. If a curved tip guide wire 24is used, the guide wire 24 will be held straight within the lumen 22 ofthe catheter 20 until the distal portion 26 of the guide wire 24 exitsthrough the side port 23. The length of the catheter 20 will helpstabilize the catheter 20 as the curved guide wire 24 is pushed throughthe catheter 20. If a straight guide wire is used, the guide wire 24must be flexible enough to deflect and bend as it enters the curvaturecontained within the catheter 20 to deflect the guide wire 24 out of theside port 23.

The catheter 20 with the side port 23 shown in FIG. 6 will torque withvery little “whip” and allow for relatively easy positioning of the sideport 23. The compressive force of the guide wire 24 necessary to deflectit through the side port 23 will result in a tensile loading on thecatheter shaft that is fairly easy to restrain.

FIG. 7 shows an embodiment of a catheter 30 in which the cathetercontains a single lumen 31 and side port 32 through which the guide wire33 is passed. The single lumen 31 truncates at its distal end 34 to theside port 32 to guide the guide wire 33 to the opening of the side port32.

FIG. 8 shows an embodiment of a catheter 40 with a side port 41 in whichone or more support balloons 42, 43 are used to stabilize the catheter40 during delivery of the guide wire 44 through the side port 41. Afirst balloon 42 can be positioned proximal of the side port 41, and asecond balloon 43 can be positioned distal of the side port 41.

FIGS. 9 and 10 show an embodiment of a catheter 50 in which a singlesupport balloon 51 surrounds the catheter 50 adjacent to the side port52 and has a recess 53 in the support balloon 51 to allow delivery ofthe guide wire 54 through the side port 52. In this case, the balloon 51can be centered over the side port 52 and attached to the outer sleeve55 of the catheter 50 at the proximal and distal ends of the balloon 51and around the side port 52.

FIG. 11 shows an embodiment of a catheter 60 in which a balloon 61having a general shape of a hotdog bun is used for stabilizing thecatheter 60. In this embodiment, the balloon 61 has an open side 62 forallowing delivery of the guide wire 63 through the side port 64. Theballoon 61 can be centered about the side port 64 and attached to theouter sleeve 65 of the catheter 60 as shown.

FIG. 12 shows an embodiment of a catheter 70 in which two lumens 71, 72are provided in the catheter. The first lumen 71 serves as the lumen fordelivering the guide wire to the side port 73, and the second lumen 72serves as a balloon inflation lumen for delivering gas or fluid to aballoon inflation port 74 for inflating the support balloon or balloonsafter insertion of the catheter 70 into a patient.

FIGS. 13 and 14 show an embodiment of a catheter 80 in which aninsertion lumen 81 is provided for inserting the catheter 80 over asecond guide wire 82 previously placed in the non-occluded portion ofthe artery 12. The second guide wire 82 can pass through the insertionlumen 81 for guiding the catheter 80 into position within a patient'sbody. As shown in FIG. 13, the insertion lumen 81 is open at both itsdistal and proximal ends 83, 84 and arranged so that the balloon and theballoon inflation port 85 and the side port 86 of the catheter 80 arelocated between the distal and proximal ends 83, 84. The insertion lumen81 passes through the inflation lumen 87 of the catheter 80.

FIGS. 15 and 16 show an embodiment of a catheter 90 in which a tubularmember 91 is provided on the exterior of the primary catheter 92. Thetubular member 91 provides an insertion lumen for a second guide wire 94used to guide the catheter 90 into position within a patient's body. Inthis embodiment, a support balloon 93 surrounds both the tubular member91 and the primary catheter 92. FIG. 17 shows a similar embodiment of acatheter 95, except that no support balloon is used.

FIG. 18 shows an embodiment of a catheter 100 in which no extension ofthe catheter extends past the side port 101. In this embodiment, amolded tip 102 is provided to facilitate movement of the exitingperforating guide wire 103.

FIGS. 19 to 21 show another embodiment of a catheter 110 in which theside port 111 is movable relative to the base portion 112 of thecatheter 110 to change the angle □ at which the guide wire 113 exits thecatheter 110. In this embodiment, the base portion 112 of the catheter110 has a molded internal guide 114 within its tip 115, and a movableportion 116 in which the side port 111 is formed. The base portion 112and movable portion 116 are telescoping members that can be adjustedrelative to one another. As the side port 111 on the movable portion 116is positioned relative to the base portion 112, the angle □ of the guidewire 113 exiting the catheter 110 will change. In other words, themovable portion 116 can be moved relative to the base portion 112 toadjust the angle □ of the guide wire 113 exiting the catheter 110. Therelative positions of the movable portion 116 and the base portion 112can be adjusted during a surgical procedure using a push/pull wire or byapplying a fluid pressure within a lumen 117 of the base portion 112.Support balloons and the like as described above can be incorporatedinto this embodiment as desired.

FIG. 22 show an embodiment of a catheter 120 in which telescopingsleeves 121, 122 are used to change the angle □ at which the guide wire113 exits the side port 111 of the catheter 110. The telescoping sleeves121, 122 will provide a convenient means by which a surgeon can adjustthe relative positions between the outer “movable” portion 121 and theinner “base” portion 122 of the catheter 120 from the proximal end ofthe catheter 120.

FIGS. 23 to 25 show another embodiment of a catheter 130 in whichtelescoping inner and outer tubes 131, 132 having offset ports 133, 134at their distal ends 135, 136 are used to change the angle at which theguide wire 137 exits the catheter 130. The inner and outer tubes 131,132 are arranged for rotational and/or telescoping movement relative toeach other. For example, the inner tube 131 can be moved in atelescoping manner relative to the outer tube 132 from the positionshown in FIG. 23 to the position shown in FIG. 24. Further, the innertube 131 can be moved in a rotational manner relative to the outer tube132 from the position shown in FIG. 24 to the position shown in FIG. 25.

The inner tube 131 has an internal lumen 138 that leads to the firstport 133 at the distal end 135 of the inner tube 131. The outer tube 132has the second port 134 at the distal end 136 of the outer tube 132. Inthe embodiment shown in FIGS. 23 to 25, the first port 133 is offsetfrom the longitudinal axis of the catheter 130, and the second port 134is approximately concentric with the longitudinal axis. In theembodiment shown in FIGS. 26 and 27, both the first and second ports133, 134 are offset from the longitudinal axis of the catheter. In bothembodiments, the first and second ports 133, 134 are offset relative toeach other so that relative movement between the inner and outer tubes131, 132 will cause relative movement between the first and second ports133, 134 to adjust an angle of the perforating guide wire 137 exitingthe catheter.

In the catheter embodiments shown in FIGS. 23 to 27, the degree ofdeflection of the guide wire 137 can be increased or decreased bytelescoping the tubes 131, 132, and/or by rotating one or both tubes131, 132 to change the alignment of the first and second ports 133, 134.The catheter 130 can also be used in combination with an inflatablestabilizing balloon as described above in connection with the otherembodiments disclosed herein.

Catheter devices according to various embodiments of the presentinvention have been described above. Methods of using these catheterdevices to access a side branch 11 of an artery 12 will now bedescribed.

The basic method includes a first step of providing a catheter 20 havinga sidewall 21 and an internal lumen 22, a side port 23 formed throughthe sidewall 21, and a perforating guide wire 24 positioned within theinternal lumen 22. A second step is to deploy the catheter 20 to alocation with the side port 23 suitably aligned with a side branch 11 ofan artery 12 to be accessed. A third step is to move the guide wire 24through the side port 23 and into the side branch 11 of the artery 12.

In the catheter embodiments having a distal portion 27 that extends pastthe side port 23, the method will include the step of positioning thedistal portion 27 on a distal side of the side branch 11 of the artery12 to stabilize the catheter 20 while the guide wire 24 is beingdelivered through the side port 11.

In the catheter embodiments having one or more balloons 42, 43 attachedto the catheter, the method may include the further step of inflatingthe balloon 42, 43 within the artery 12 to stabilize the catheter whilethe guide wire 44 is being delivered through the side port 41. Asdescribed above, a first balloon 42 can be positioned proximal of theside port 41 and a second balloon 43 can be positioned distal of theside port 41.

In the catheter embodiments having an insertion lumen 81, the method mayinclude the further step of guiding the catheter within a patient's bodyover a second guide wire 82 that passes through the insertion lumen 81.As described above, the insertion lumen 81 has open distal and proximalends 83, 84 and is arranged so that the side port 86 of the catheter islocated between the distal and proximal ends 83, 84.

In the catheter embodiments having a base portion 112 and a movableportion 116 with the side port 111 formed in the movable portion 116,the method may include the further step of moving the movable portion116 relative to the base portion 112 to adjust an angle □ of the guidewire 113 exiting the catheter.

Referring now to FIG. 28, there is shown an alternative embodiment of acatheter assembly according a further aspect of the present disclosure.The embodiment 200 retains all of the features of FIG. 8 described indetail above, but further includes an on-board imaging system 220. Theimaging system is spaced distally by a distance D1 from the sidewallopening 41. In one aspect, D1 can vary from about 1 mm to about 1 cmdepending on the desired spacing which may be a function of spaceconstrains within the catheter and the desired imaging angle of thefield of view illustrated by dashed lines 230. Typically, the field ofview will be oriented between 90 and 45 degrees outwardly from thecatheter side wall such that the expected side branch or tissue ofinterest will be within the primary field of view when deployed within avessel. As illustrated, a marker element 232 is positioned within thefield of view of the imaging system 220 radially aligned about thelongitudinal axis to be in alignment with the sidewall opening 41. Asshown in more detail with respect to FIGS. 32-34, the marker element 232provides a visual indication, during imaging, of the orientation of thesidewall opening with respect to surrounding tissue structures and theimages viewed on a display screen. Referring now to FIGS. 29 and 30, thecatheter system previously described with respect to FIGS. 9-11 has beenenhanced to include an on-board imaging system 240. As previouslydiscussed, the system include a visualization marker 242 radiallyaligned at the some radial or angular location about the longitudinallyaxis of the catheter, but offset longitudinally, from the side wallopening 64. The imaging systems 220 and 240 may be used to locate thearea of interest prior to balloon inflation. Once the area isidentified, the balloons of FIG. 28 or the single balloon of FIG. 29 canbe inflated to maintain the catheter system in a fixed location allowingthe imaging system to monitor the occlusion 10 while deploying thecrossing wire. The balloon systems may be particularly useful foroptical imaging systems as the blood in the vessel may be displaced by afluid, such as saline, distal of the balloons for better imaging.

Referring now to FIG. 31, there is shown still a further embodiment of atreating catheter incorporating a steerable crossing wire assembly withan on-board imaging system positioned to aid in the deployment andnavigation of the crossing wire as it is extended outside of thedelivery catheter. The treating catheter 260 is deployed within thelumen 252 of primary vessel 250. The treating catheter 260 is shownafter having been positioned on guide wire 262 by use of the monorailassembly 264. The distal tip 266 containing imaging system 268 has beenpositioned slightly beyond side branching vessel 290. The imaging system268 has been used to locate the position of the side branching vessel290 containing an occlusion 292 and has been oriented such that visualmarker 273 is oriented to radially align with the side branching vessel290. As illustrated, the visual marker is aligned with the side wallopening 270. Thus, the crossing wire 272 can be manipulated by thesteering catheter 280 to exit the side wall opening 270 adjacent theside branching vessel 290. As explained more fully above, movement ofthe steering catheter 280 within the delivery catheter 265 changes theposition of the opening 280 with respect to opening 270 such that thecrossing wire 272 is effectively guided as it exits the deliverycatheter. As shown in FIG. 31, the steering mechanism is moved withinthe delivery catheter to position the tip 274 of the crossing wire 272in contact with the surface 294 of the occlusion 92.

Referring now to FIG. 32, there is shown a partial cross sectionaldiagrammatic view of the treating system 260 incorporating anoscillatory imaging system 268. The oscillatory imaging system 268utilizes a single transducer 269 that is oscillated through an arc ofbetween 120 and 360 degrees to form an image. Cable 267 provides powerto drive the oscillation and carry signals to and from the ultrasoundtransducer 269. In the illustrated embodiment, the arc defines a fieldof view FV that is angled backwards toward the opening 270 such that thefield of view FV encompasses tissue disposed radially outward from theopening 270. As discussed above, a marker 273 is positioned on thecatheter (or within a component of the imaging system) within the fieldof view such that when the field of view is output on a display device auser can determine the orientation of the marker 273 and aligned opening270 in relation to the imaged tissue surrounding the catheter.

Referring now to FIG. 33, there is shown still a further embodiment of atreating system 260′ having an alternative imaging system 268′. Thecrossing wire steering components of the system are the same as setforth above. In the illustrated embodiment, the imaging system 268′ is a360 degree imaging system that has a field of view that includes alltissue surrounding the catheter in a 360 degree revolution. Exemplarysolid-state IVUS systems usable as the imaging system 268′, alsoreferred to as phased-array imaging systems, are described, for example,in U.S. Pat. No. 6,283,920 and U.S. Pat. No. 6,283,921, each of which isincorporated herein by reference in their entirety. Such solid-statesystems typically have lower resolution but higher depth of penetrationthan rotational systems. Although the imaging system may utilize a fieldof view oriented at 90 degrees from the catheter, as shown in FIG. 33,the exemplary field of view FV′ has been angled rearward at an angle ofapproximately 45 degrees to define a conical field of view. The field ofview FV′ includes a visual marker 273′ aligned with opening 270. In analternative aspect, the imaging system 268′ could include a singleimaging element continuously rotated about an axis.

Referring now to FIG. 34, there is shown an example of a display device400 showing a display 300 outputting a field of view FV′ from theimaging system 268′. The image 300 illustrates a position of the imagingdevice at location 305, primary lumen 252 of the vessel at 315, sidebranching vessel lumen 290 at location 320 and visual marker 273′ at thelocation designated by arrow 300. As illustrated, the arrow 330 pointsthe direction that the crossing guide wire 272 will be exiting opening270. Thus, the user can use the visual marker 330 to align the sideopening 270 with the branching side vessel 290 as shown in FIG. 34.

As a further feature, the sensed image data received from imaging system268′ may be further processed by a tissue characterization system. Inone feature, the system may identify and display lumen or vessel wallboundaries illustrated by lines 310 on the image 300, along withdetermining the tissue characteristics of the occlusion 292. In still afurther feature, tissue characterization may be used to identifyadventitial tissue to alert the user of the location of the adventitialtissue to prevent unwanted penetration outside of the vessel wall. Asystem and method of adventitial tissue characterization is disclosed inU.S. Patent Application Ser. No. 61/784,570 filed Mar. 14, 2013,entitled: SYSTEM AND METHOD OF ADVENTIAL TISSUE CHARACTERIZATION,incorporated by reference herein in its entirety.

Alternatively, the occlusion crossing guide wire may be replaced with atreatment device such as an ablation electrode or a suturing device. Itwill be appreciated that with alternative treatment devices steered withthe control system described herein as aided by the above describedimaging system, that ablation therapies and structural heart repairsmaybe accomplished with precision using the combination of mechanicalsteering control and on-boarding imaging adjacent the treatment device.

The above described imaging systems have been illustrated utilizing anultrasound imaging system as an example. However, these examples areprovided only for the purpose of illustration and the present conceptsare not limited to the type of imaging system utilized. Any type ofimaging system may be incorporated with the mechanical steering systemdescribed above including, for example, but without limitation, opticalsystems, optical coherence tomography (OCT), photoacoustic sensors,optical IVUS, and spectroscopy.

A specific method of using the treating system 260 will be describedbelow, although any of the treating systems disclosed above can bemodified to incorporate an imaging system as described and used in asimilar manner. Referring to FIG. 31, as an initial step, a guide wire262 is positioned in the primary vessel 252 and the treating system 260is advanced along the guide wire until it is positioned in the area ofthe occluded side branching vessel 290. As shown in FIG. 34, the imagingsystem may be moved along the guide wire until the field of viewdisplays an image illustrating a side branching vessel. Once the sidebranching vessel has been identified, the treating system catheter 260is rotated until the visual marker 273 (as indicated by the marker 330on the display) is aligned with the side branching vessel (as indicatedby region 320 on the display). Once properly aligned, a user may movethe treating device longitudinally along the guide wire to determine thewidth of the opening of the side branching vessel and its locationrelative to the distance D1 between the side wall opening 270 and theimaging system 268. Once the opening 270 has been rotationally orientedand longitudinally oriented to be disposed adjacent the side branch 290,the steering catheter 280 is manipulated within the delivery catheterwith respect to opening 270 to change the orientation and/or trajectoryof the longitudinal axis LA of crossing wire 270 as it exits opening270. As shown in FIG. 31, the longitudinal axis LA is oriented to extendacross the occlusion 292 without penetration side walls of the vessel290. As described above, the imaging system 268 can be used to identifyboundaries of the vessel 290 along with using tissue characterization todetermine the tissue type of the material making up the occlusion 292.In this manner, the crossing wire can be safely guided across theocclusion. Once a safe path is identified, the crossing wire 272 can beadvanced into and across the occlusion 292. During advancement of thecrossing wire 272, the imaging system may be continuously activated sothat the position of the crossing wire 272 in relation to the vessel 290is constantly monitored in real time. The monitoring may includeobservation of the actual location of the crossing wire as well as aprojection of the expected path or trajectory of the crossing wire toavoid inadvertently passing through or otherwise perforating the lumenof the vessel. In some applications, such as subintimal tracking, theimaging system may be utilized to characterize vessel tissue and/oridentify borders between vessel wall tissue segments. For example, theimaging system provides display information to the user identifying theboundary of the intima. The user may then use the steering assembly toorient the alignment of the crossing wire to extend along a subintimalpath. The process of displaying, identifying and aligning the crossingwire to remain in the subintimal path continues until the crossing wirehas been advanced beyond the occlusion. Once beyond, the occlusion asindicated by the imaging system, the steering mechanism can be actuatedto cause the crossing wire to change orientations such that furtheradvancement penetrates the intimal tissue and re-enters the lumen of thevessel beyond the occlusion.

In a further aspect, an external imaging system, such as a flurosystem,may be used to image the treating catheter in an image plane that isgenerally perpendicular to the imaging plane of the imaging system 268.In one aspect, the display 400 includes both an image 300 from theimaging system and an image from the flurosystem. In another aspect, amulti-dimensional model is generated based on inputs from the imagingsystem 268 and another imaging system and the resulting data isdisplayed to a user. In this form, the resulting data provided ondisplay 400 may include colorized portions indicating vessel structures,tissues, and the crossing wire. In this form, both the output of theimaging system 268 and the output of the flurosystem may be used toposition the treating device, identify a path for crossing the occlusionand monitor progression of the crossing wire as it extends from thedelivery catheter.

Although the above method of use has been described in relation tocrossing a vessel occlusion, it will be appreciated that the system canused to treat structural tissue defects as well. In one example, thetreating system may be guided to a patient's heart. The imaging system268 is used to image tissue within the heart, such as a valve or a wall,to identify a defect. Once the defect is identified, the treating deviceis rotated about the longitudinal axis to align the visual indicatorwith the identified defect. If necessary, the longitudinal position ofthe opening in the catheter where the treating device exits can beadjusted so the treating device is properly aligned with the tissue tobe treated. The treating device can then be steered by the controlsystem to exit the catheter and extend in a direction toward the tissueto be treated. For a heart valve or structural wall defect, the treatingsystem may include a tacking or tissue joining device, such as a T-bar,for joining one tissue structure to another. Alternatively, the treatingsystem may include an ablation device to damage tissue. The imagingsystem may be utilized to monitor the therapy being delivered in realtime. During treatment monitoring, the location of the treatment devicemay be adjusted by the steering assembly based on image data displayedto the user.

While the invention has been described in connection with specificembodiments thereof, it is to be understood that this is by way ofillustration and not of limitation, and the scope of the appended claimsshould be construed as broadly as the prior art will permit.

What is claimed is:
 1. A method of crossing an occlusion within avessel, comprising: positioning a catheter within a vessel of a patient,the catheter including an imaging element, a steering assembly and anocclusion crossing wire extendible through an exit opening in thecatheter; advancing the imaging element through a main vessel to aposition adjacent an occlusion of a side vessel; imaging the occlusionalong with a portion of the side vessel; aligning the exit opening withthe occlusion; changing an orientation of the crossing wire with thesteering assembly; and advancing the crossing wire through the exitopening and into the occlusion.
 2. The method of claim 1, whereinimaging includes evaluating tissue characteristics of at least one ofthe occlusion and the side vessel.
 3. The method of claim 1, wherein thecatheter includes a marker detectible by the imaging element, and thealigning further includes rotationally aligning the marker with the sidevessel.
 4. The method of claim 1, wherein the imaging includesactivating at least one ultrasound transducer.
 5. The method of claim 1,wherein the imaging includes activating an optical coherence tomographysensing system.
 6. The method of claim 1, wherein the steering assemblyincludes an inner catheter positioned within the catheter, the crossingwire extending within at least a portion of the inner catheter andexiting a distal opening; and further including moving the innercatheter with respect to the exit opening to thereby change thealignment of the crossing wire before advancing the crossing wirethrough the exit opening.
 7. The method of claim 1, further includingimaging the side branch vessel and the crossing wire during theadvancing the crossing wire through the exit opening and into theocclusion.
 8. The method of claim 7, further including adjusting thepath of the crossing wire utilizing the steering assembly based on theimaging during the advancing of the crossing wire.
 9. A method oftreating an internal structure within a patient, comprising: positioninga catheter adjacent a structure to be treated, the catheter including animaging element, a steering assembly and a therapy delivery deviceextendible through an exit opening in the catheter, the steeringassembly operable to adjust the trajectory of the therapy deliverydevice as it extends through the exit opening; advancing the imagingelement to a position adjacent the structure to be treated; imaging thestructure to be treated with the imaging element; aligning the exitopening with the structure to be treated; and advancing the therapydelivery device through the exit opening and toward the structure to betreated.
 10. The method of claim 9, wherein the structure to be treatedis an occlusion within a vessel.
 11. The method of claim 9, wherein thestructure to be treated is a valve.
 12. The method of claim 9, whereinthe structure to be treated is an opening in a tissue wall.
 13. A vesselocclusion crossing system comprising: a catheter body having a lumen, animaging element disposed on a distal portion of the catheter; a crossingwire slidably disposed within at least a portion of the catheter; and asteering assembly for changing the direction of the crossing wire afterexit from the catheter assembly.
 14. The system of claim 13, wherein theimaging element includes an ultrasound transducer.
 15. The system ofclaim 13, wherein the imaging element comprising an array of ultrasoundtransducers.
 16. The system of claim 14, wherein the ultrasoundtransducer is rearward looking away from a distal end of the catheterbody.
 17. The system of claim 13, wherein the ultrasound transducer islight based.
 18. The system of claim 13, further including acommunication connector coupled to the imaging element, thecommunication connector extending within at least a portion of thecatheter.
 19. The system of claim 18, the communication connector isembedded into a sidewall of the catheter
 20. The system of claim 12,further including a balloon carried by the catheter.